The present invention relates to a traction slip control device comprising a sensor which responds to a beginning slip condition on at least one of the driving wheels to provide a slip signal and, a control circuit which, via an auxiliary drive, actuates the throttle valve of the drive engine in the closing sense when the sensor feeds a slip signal to the control circuit.
It is a purpose of these devices that, upon the occurrence of spinning of one of the driving wheels, the throttle-opening forces exerted by the accelerator pedal are overridden in the sense that, on beginning wheel slip, continued opening of the throttle valve as an inevitable consequence is avoided, or, to eliminate wheel slip, the throttle valve is adjusted in the closing direction by an amount required therefor. After wheel slip has been eliminated, the traction slip control device is set out of function again, whereupon the throttle valve will be acted upon by the accelerator pedal in the normal and conventional manner. In general, the control operations initiated by the sensor and the control circuitry are performed in a rhythmical way. That means the pressure application and the pressure relief, respectively, of the wheel cylinders takes place with a comparatively high sampling frequency. In consequence thereof, it is difficult to use simple piston-cylinder assemblies for the actuation of the accelerator linkage. Therefore, electric motors have been used so far for an intervention in the setting of the throttle valve.